He's demanding. Oh, boy is he demanding. He's there, yelling "Look at me, listen to me, talk to me. Pay attention to me now".
He's selfish. He knows what you are doing might be important, but he is more important, and he expects you to make it quite clear that you know that.
He's sneaky. He hides his demands behind shows of affection so you won't yell at him when he distracts you.
He's spiteful. If he doesn't get his way, he'll get his own back, sooner or later.
He's easily hurt, but you can kiss it all better. He only does these things because he needs the attention, to feel special and wonderful and essential.
If he gets what he wants, he's a little angel, and he'll do anything for you.
And, sometimes, he's uncontrollable.
In fact, he's almost identical to the little girl who's hiding inside every woman. Except he's louder. On the other hand, he doesn't stamp his feet as often.